The invention relates to an inductive component with a coil body which features a coil space delimited by an exterior flange and a winding tube, which features contact strips molded onto the exterior flange, and which has contact elements and wire guide slots which progress into the contact strips.
A coil of this nature is essentially known from European Patent Specification EP 0 594 031. These inductive components, primarily in the form of coils or repeaters, also featuring subdivided coil spaces, must satisfy elevated demands for surge voltage resistance and creep resistance. During the assembly of circuit boards with other electronic components, voltages of 200 V or more can occur between the coils. Consequently, it is necessary to wrap the coil body in such a way that buckling and bending stress exerted on the coil wire is as low as possible and that the coil itself is as uniform as possible. A uniform coil structure can also be necessary to satisfy electrical specifications for inductance. The relevant standards, such as EN60950 which applies to telecommunications applications and calls for creep resistance, must be observed in the respective specific applications of such coils or repeaters.
The coil ends, which must be connected to the contact elements, can be guided in the contact strips through wire guide slots. In practice, the first and each successive coil is attached to the inner surface of the flange with adhesive tape (barrier tape) and separated from the respective adjacent coil, so as to ensure creep resistance between the core and the first coil, on the one hand, and among the coils themselves, on the other hand. However, tension is exerted on the first coil and/or the inner coils as soon as the second coil and each ensuing coil is applied during production of the inductive component.
Therefore, the object of the invention is to specify an inductive component of the type mentioned initially, but with improved properties.
In the invention, this object is solved by the features of claim 1. Embodiments of the invention are characterized in subclaims.
An advantage of the invention is that the segment of the wire of the first coil that progresses away from the winding tube and toward the contact elements and/or the take-up pins of the contact elements has no or only minor frictional contact with the second or higher coil, thus resulting in lower tensile stress on the coil wire. This applies analogously to the ensuing coils, i.e., to the second coil when the third is applied, etc., if more than two coils are provided. The greatest advantage, however, arises with the first, innermost coil, because the distance between it and the contact strip is greatest.
Another advantage comprises the fact that the accuracy of the coiling process is increased during production of the component.
Advantageously, the barrier tape can be easily and securely applied laterally to the inside of an exterior flange because the coiling wire in this region is, for the most part, disposed in the wire guide slot and is at best only slightly disposed on the inside of the exterior flange.
Another advantage of the invention comprises the fact that, due to the progression of the terminal portion of the coil wire within the wire guide slots, the homogeneity of the layer structure of the coils is significantly improved, especially in higher coil layers. This makes it possible to design the inductive component as a surface-mountable component and, due to the homogeneous coil structure, to automate the configuration process (pick and place). At the same time, the coiling process of the inductive component can be managed in an accurately controlled manner.
An advantage of the invention comprises the fact that, because of the low buckling and bending stress exerted on the coil wire in the connection zones and because of the fact that the wire is guided through the wire guide slots, the surge voltage resistance and creep resistance of the component are improved.
In the following, the invention is explained in greater detail on the basis of four figures, in which identical elements are identified with the same reference numbers. Shown are in